Sealing High Pressure Flow Devices

ABSTRACT

Apparatus and method contemplating a high pressure fluid end assembly having a body defining a body bore and defining a recess in the body intersecting the body bore. A closure is joined to the body and forms a sealing surface. A seal is mounted to the body in the recess and configured to extend from the recess beyond the body bore to seal against the sealing surface formed by the closure.

BACKGROUND

This technology relates generally to sealing fluid flow passages insideflow control devices, such as those particularly suited for use in highpressure oil and gas production and processing systems.

One such type of flow control device is a valve. Generally, a valveforms a flow passage and has a selectively operable closure to open orclose the flow passage in order to control a flow of fluid through thevalve. The sealing integrity of high pressure valves must withstand notonly high operating fluid pressures, presently 15,000 pounds per squareinch and higher, but also must do so while controlling the flow ofcorrosive and/or abrasive fluids that are notorious for eroding thevalve internal components in the oil and gas industry. Preferably, thevalves can withstand pressures up to at least 22,500 pounds per squareinch.

Illustrative embodiments herein are directed to a plug valve althoughthe contemplated embodiments are not so limited. In a plug valve theflow passage typically includes a valve body in fluid communication withtwo or more openings, typically an inlet opening and an outlet opening,forming a flow passage through the valve body. A valve plug and insertsegments, one type of a valve closure that is described herein, aredisposed in a valve body bore between the inlet and outlet openingswhere sealing occurs between the plug, the insert, and the bore. Thevalve plug defines a through-opening and is selectively rotatable to anopen position where the through-opening is aligned with the flow passageto permit a flow of fluid through the valve (from the inlet to theoutlet), or to a closed position where the through-opening is misalignedwith the flow passage to prevent the flow of fluid through the valve.Operating a valve in the harsh oilfield conditions can cause erosion ofthe valve body bore where the seal in the insert abrades against thebore, often resulting in leakage in a short amount of time. Repairingthe valve body, such as by a weld build-up and machining operation, is acumbersome and disruptive repair in the oilfield.

The illustrative embodiments of this technology directed to plug valvesare in no way limiting of the contemplated embodiments of thistechnology. The skilled artisan understands that in alternativeembodiments this technology can be used in other types of valves havingdifferently configured closures. However, an enumeration of all thedifferent types of valves that are suited for using this technology isnot necessary for the skilled artisan to understand the scope of theclaimed subject matter, so no such enumeration is warranted.

Besides valves, other types of high-pressure flow devices are alsosuited for practicing this technology. For example, a fluid end is usedin many well servicing applications to contain high pressure, oftencorrosive and/or abrasive, fracturing fluids in the oil and gasindustry. A fluid end typically has a manifold body and a number ofcomponents mounted and sealed to the body, such as the suction anddischarge plugs, suction and discharge valve seats, stuffing box,discharge flange, and suction manifold; with those components eitheralone or sleeved as are illustratively described herein. Like thevalves, operating a fluid end in the harsh oilfield conditions can causeerosion of the body resulting in leakage in a short amount of time.Repairing the body is also cumbersome and disruptive in the oilfield.

Improvements are needed in the internal sealing of high pressure flowdevices to increase operating life while reducing downtime and operatingcost. What is needed is a solution that transfers the erosion (corrosionand abrasion) from the high pressure fluid device body to the componentsealed with the body. It is to those improvements that embodiments ofthis technology are directed as described in the illustrativeembodiments and contemplated within the scope of the claims.

SUMMARY OF THE INVENTION

The present invention is directed to a fluid end assembly comprising ahousing having an external surface and an internal chamber, and a firstconduit formed in the housing and having first and second sections, eachsection independently interconnecting the internal chamber and theexternal surface. The fluid end assembly further comprises a secondconduit formed in the housing, intersecting the first conduit andindependently interconnecting the internal chamber and the externalsurface, and an endless groove formed in the wall or walls defining oneof the conduits and extending concentrically around that conduit.

The present invention is also directed to a fluid end assemblycomprising a housing having an internal chamber and a conduit thatintersects the internal chamber and opens at a first surface of thehousing, a plunger that reciprocates within the housing, and a sealpositioned within an annular groove formed in the housing.

The present invention is further directed to a method for manufacturinga fluid end assembly. The method comprises the steps of providing ahousing having an external surface, an internal chamber, a first conduitformed in the housing having first and second sections, and a secondconduit formed in the housing, intersecting the first conduit and havingthird and fourth sections independently interconnecting the internalchamber and the external surface, and forming an endless groove in thewalls or walls defining one of the sections such that the groove extendsconcentrically around that section.

The present invention is also directed to a fluid end assembly having ahousing having an external surface and an internal chamber, a firstconduit formed in the housing and having first and second sections, anda second conduit formed in the housing, intersecting the first conduit.The fluid end assembly further comprises a recessed corner sectionformed in the wall or walls defining one of the conduits and extendingconcentrically around that conduit. The corner element is sized toreceive a sealing element therein. The fluid end assembly furthercomprises a stuffing box installed in the same conduit within which thecorner section is formed and having a tubular side wall that fullyoverlies that corner section. Each conduit independently interconnectsthe internal chamber and the external surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of various embodiments of the present technology are describedin connection with the accompanying drawings that bear similar referencenumerals.

FIG. 1 is a cross-sectional depiction of a plug valve that isconstructed in accordance with previously attempted solutions.

FIG. 2 is a cross-sectional depiction of another plug valve that isconstructed in accordance with other previously attempted solutions.

FIG. 3 depicts enlarged portions of the plug valve in FIG. 1.

FIG. 4 depicts enlarged portions similar to FIG. 3 but of a plug valvethat is constructed in accordance with embodiments of this technology.

FIG. 5 depicts more of the plug valve of FIG. 4.

FIG. 6 is a cross-sectional depiction of another plug valve that isconstructed in accordance with this technology.

FIG. 7 is an isometric depiction of a valve insert in the plug valvedepicted in FIG. 1.

FIG. 8 is similar to FIG. 7 but depicting a different cross-sectionthrough the plug valve.

FIG. 9 is an isometric depiction of a fluid end that is constructed inaccordance with embodiments of this technology.

FIG. 10 is an enlarged depiction of a portion of the fluid end of FIG.9.

FIG. 11 is an exploded cross-sectional depiction of a fluid end that isconstructed in accordance with embodiments of this technology.

FIGS. 12 and 13 are enlarged depictions of portions of the fluid end ofFIG. 11.

FIG. 14 is a cross-sectional depiction of another fluid end that isconstructed in accordance with embodiments of this technology.

FIGS. 15 and 16 are enlarged depictions of portions of the fluid end ofFIG. 14.

DETAILED DESCRIPTION

Initially, this disclosure is by way of example only, not by limitation.The illustrative constructions and associated methods disclosed hereinare not limited to use or application for sealing any specific assemblyor in any specific environment. That is, the disclosed technology is notlimited to use in sealing valves and fluid ends as described in theillustrative embodiments. Thus, although the instrumentalities describedherein are for the convenience of explanation, shown and described withrespect to exemplary embodiments, the skilled artisan understands thatthe principles herein may be applied equally in sealing other types ofhigh pressure flow devices.

FIG. 1 is a cross-sectional depiction of a plug valve 100 that isconstructed according to previously attempted solutions. The plug valve100 has a forged valve body 102 forming a tapered internal bore 104.Inserts 106 a, 106 b in these illustrative embodiments are segments ofan open hollow cone. Although two inserts 106 a, 106 b are depicted, thecontemplated embodiments are not so limited because alternatively therecan be more than two. Each insert 106 a, 106 b has an outer conicalsurface 108 a, 108 b forming a matching taper to engage against the bore104 in a close mating relationship.

A cylindrical plug 110 has an outer diameter surface 112 sized to fillthe space between the inserts 106, mating with an inner diameter surface114 a, 114 b of the respective inserts 106. The plug 110 has a topjournal 118 that is rotatable within a retaining nut 120. A packing 122seals against the journal 118 to contain the pressurized fluid insidethe valve 100 while permitting an external force to rotate the journal118 and, in turn, the plug 110. In these illustrative embodiments ahandle 124 is connected to the journal 118 to permit a user to manuallyrotate the plug 110. In alternative embodiments not depicted the journal118 can be rotated by a powered actuator. The plug 110 also has a bottomjournal 126 that rotates within the body 102 and is sealed by packing128.

The body 102 also forms openings 116 a, 116 b intersecting the bore 104,typically referred to as an inlet and an outlet. For illustrativepurposes of this description it is a given that the fluid flows throughthe valve 100 from left to right, or into the opening 116 a and out ofthe opening 116 b. However, in practice either opening 116 can providethe inlet and the other opening 116 the outlet.

Each insert 106 forms a respective opening 130 a, 130 b, and the inserts106 are mounted in the valve 100 so that the insert openings 130 arealigned with the respective valve body opening 116. The plug 110 forms athrough-opening 132 permitting a user to selectively align the opening132 with the openings 116. FIG. 1 depicts the closed position of thevalve 100, where the plug 110 is rotated so that the through-opening 132is misaligned with the openings 116.

Namely, in the closed position of the valve 100 depicted in FIG. 1,pressurized fluid connected to the opening 116 a (inlet) impacts againstthe closed plug 110, sealing the backside of the plug in ametal-to-metal seal against the insert 106 b and also sealing between aseal 140 mounted in the insert 106 b between it and the valve body bore104. Thus, in the closed position the pressurized fluid is blocked fromflowing through the valve 100. By rotating the plug 110 to the openposition (not depicted), its through-opening 132 comes into alignmentwith the openings 116, permitting the pressurized fluid to flow throughthe valve 100 via a flow passage established collectively by the valvebody openings 116, the insert openings 130, and the valve plugthrough-opening 132.

FIG. 2 is similar to FIG. 1 but depicting a top entry plug valve 100′that is constructed in accordance with other previously attemptedsolutions. The plug valve 100′ has inserts 106 a′, 106 b′ that areformed as segments of an open hollow cylinder instead of the inserts 106a, 106 b in FIG. 1 that are segments of an open hollow cone. In otherwords, the conical surfaces in FIG. 1 are replaced here with cylindricalsurfaces. Due to this, the inner body of the plug valve 100′ is nottapered, unlike the plug valve 100. For purposes of this description theskilled artisan understands that the details of construction and use ofthis technology applies equivalently to both types of these valves, aswell as other types of valves that are used to control highlypressurized fluid. Thus, the skilled artisan understands the scope ofthe claims from this description's comparison to the details ofconstruction for just one of the previously attempted solutions.

Continuing with the previously started description in comparison to thepreviously attempted solutions depicted in FIG. 1, FIG. 3 is an enlargedportion of it more particularly depicting how the high pressure fluid iscontained inside the valve 100 in part by the seal 140 that iscompressed between the outer conical surface 108 b of the insert 106 band the valve body bore 104.

The insert 106 b has a surface 139 defining a recess 144 intersectingthe outer conical surface 108 b. The term “intersecting” for purposes ofthis description and meaning of the claims means that the recess 144forms a gap in the outer surface 108 b of the insert 106 b. Thatintersecting construction of the recess 144 with the surface 108 bpermits mounting a fixed end 141 of the seal 140 in the recess 144, andsizing the seal 140 so that a distal end 143 extends from the recess 144beyond the outer conical surface 108 b in order to seal against thevalve body bore 104. Importantly, this requires the bore 104 to define asealing surface 142 against which the seal 140 in the insert 106 bpresses against to effect the sealed engagement of the insert 106 bagainst the bore 104. Corrosive and/or abrasive fluid can become trappedbetween the seal 140 (mounted in the insert 106 b) and the bore 104causing erosion of the bore 104. The seal 140 in these embodiments isreferred to as an axial seal because the compressive forces from thesurface 108 b on one side and the bore 104 on the other side act in anaxial direction relative to the annular seal 140.

Although the embodiments of FIG. 3 depict only one annular seal 140surrounding the outlet 116 b, the previously attempted solutions are notso limited. The skilled artisan understands that in alternativeconstructions more than one seal can be used to provide redundancy. Theseal 140 can be an elastomeric seal, and in other embodiments otherkinds of seals can be used such as metal seals, spring seals, and thelike.

To enclose the valve plug 110 and support the journal 118, a retainingnut 120 is threaded to the valve body 102. The retaining nut 120 sealsto the valve body bore 104 by another seal 146. Similar to the insert106 b, the retaining nut 120 has a surface 147 defining a recess(sometimes referred to as a “gland”) 148 intersecting an outer diametersurface 121 of the retaining nut 120. The seal 146 is supported in therecess 148 and is sized to extend beyond the outer surface 121 to sealagainst a sealing surface formed by the valve body bore 104. The seal146 in these embodiments is referred to as a radial seal because thecompressive forces from the cap's surface 121 on one side and the bore104 on the other side act in a radial direction relative to the annularseal 146. Although a radial seal is depicted, in alternative embodimentsan axial seal or a crush seal and the like can be used instead of or inaddition to the radial seal.

In comparison, FIG. 4 is similar to FIG. 3 but depicts a portion of avalve 150 that is constructed in accordance with embodiments of thistechnology. Here an insert 151 is similar in some respects but does nothave a seal mounted to it like the insert 106 b (FIG. 3). Particularly,the insert 151 has an outer conical segment surface 153 that does notform a recess for mounting a seal. There is no gap in the surface 153where a recess intersects for mounting a seal. Instead, a valve body 152defines a valve body bore 154, and also has a surface 155 defining arecess 156 intersecting the bore 154. Again, the term “intersecting” forpurposes of this description and meaning of the claims means that therecess 156 includes a gap in the bore 154. Particularly, a fixed end 157of a seal 158 is mounted in the recess 156, and because the recess 156intersects the bore 154, the seal 158 can be sized to extend from therecess 156 beyond the bore 154 so that a distal end 159 of the seal 158seals against a sealing surface formed by the insert 151.

Corrosive and/or abrasive fluid can become trapped between the seal 158(mounted to the body 152) and the insert 151 causing erosion of theouter cylindrical surface of the insert 151. Importantly, in comparisonto the previously attempted solutions, the construction of FIG. 4advantageously transfers the erosion wear from the bore 154 (of the body152) to the insert 151. When erosion has progressed to the extent thatleakage occurs, repairing or replacing the insert 151 is significantlyless complex and less expensive than repairing the body 152.

The body 152 also has a surface 161 forming another recess 160 thatintersects the valve body bore 154. A seal 162 is mounted to the body152 in the recess 160. Again, because of the intersecting constructionof the recess 160 and the bore 154, the seal 162 can be sized to extendbeyond the bore 154 to seal against a sealing surface formed by aretaining nut 164. Unlike the retaining nut 120 in FIG. 3, retaining nut164 does not have a seal mounted to it. Instead, the seal 162 is mountedto the valve body 152 and is sized to extend from the recess 160 to sealagainst the outer diameter surface 166 of the retaining nut 164. In thesame way as described above, this technology transfers the erosion wearaway from the body 152 to the less complex and less expensive matingcomponent, in this case the retaining nut 164.

FIG. 5 is a simplified depiction of the valve 150 that is constructed inaccordance with the present technology. The skilled artisan understandsthat variations in construction are encompassed within the contemplatedembodiments of this technology that are represented in the illustrativeembodiments. For example, FIG. 6 depicts another valve 170 that isconstructed in accordance with this technology because each of the seals172, 174, 176 are mounted in respective recesses formed in the valvebody 184 and intersecting the valve body bore 178. The seals 172, 174,176 are configured to extend away from the respective recesses to sealagainst sealing surfaces of the inserts 180 and the retaining nut 182,correspondingly. Unlike the previously attempted solutions, thisconstruction eliminates the erosion caused by mounting a seal to amating component that seals against the valve body bore 178.

FIG. 7 is an isometric depiction of the insert 106 in the previous valvedesign depicted in FIG. 1. In these embodiments the insert 106 definesslots 171 intersecting the outer conical surface 108 of the insert 106.A spring 173 is mounted to the insert 106 in each slot 171 and extendsfrom the slot 171 to contact the valve body bore 104 (FIG. 1). Asdescribed above, that construction of the previously attemptedsolutions, by design, makes the valve body bore 104 the sacrificialmember for any erosion caused by the springs 173.

FIG. 8 depicts a portion of the valve 150 (of this technology) in FIG.5, but at a different cross section that passes through a recess 170′defined by a surface 190 formed by the valve body 152′. The recess 170′intersects the valve body bore 154′ so that a spring 172′ can be mountedin the recess 170′ at a fixed end and sized to extend from the recess170′ to pressingly engage against an outer conical surface 108′ of theinsert 106′. Like described above, this technology transfers the wearfrom the valve body bore 154′ to the less complex and less expensiveinsert 106′.

Returning momentarily to FIG. 5 that depicts the plug valve 150constructed in accordance with embodiments of this technology. Theskilled artisan having read this description understands that thistechnology transfers the erosion wear from the bore of the body 152 tothe outer conical surface of the insert 151. As described, leakage canoccur because the free end of the seal 158 abrades away the outerconical surface of the insert 151. In some illustrative embodiments therepair procedure can entail resurfacing the insert 151 to provide a newsealing surface for the seal 158 mounted in the body 152. Alternatively,the insert 151 can simply be replaced with a new one.

In yet other alternative embodiments a disposable wear member can beprovided between the outer conical surface of the insert 151 and thebore of the body 152. For purposes of this description and the claimsthe disposable wear member can be a disposable liner (not depicted) withone surface facing the bore of the body 152 to function effectively thesame as the outer conical surface of the insert 151. In some embodimentsan opposing inner surface of the liner can mate directly to the outerconical surface of the insert 151. Alternatively, a seal can be providedbetween the inner surface of the liner and the outer conical surface ofthe insert. That seal can be mounted to the insert and extending to sealagainst a sealing surface formed by the liner (such as by using theinsert 106 in FIG. 1), or the seal can be mounted to the inner surfaceof the liner and extending to seal against a sealing surface formed bythe outer surface of the insert.

Turning to another type of flow device that is well-suited forpracticing this technology, FIG. 9 is a simplified isometriccross-sectional depiction of a hydraulic fracturing fluid end 200 thatis constructed in accordance with previously attempted solutions. Thefluid end 200 is generally a manifold 201 used to deliverhighly-pressurized corrosive and/or abrasive fluids, typically used inhydraulic fracturing processes in the oil and gas industry. Fluid maypass through the fluid end 200 at pressures that range from 5,000-15,000pounds per square inch (psi). Fluid ends 200 used in high pressurehydraulic fracturing operations typically move fluid at a minimum of8,000 psi. However, normally, the fluid end 200 will move fluid atpressures around 10,000-15,000 psi.

The manifold body or housing 201 typically has a first conduit 220 and asecond conduit 221 formed within the body 201 that intersect to form aninternal chamber 222. The first conduit 220 is typically orthogonal tothe second conduit 221. The first conduit 220 may have aligned first andsecond sections 223 and 224 that are situated on opposite sides of theinternal chamber 222. Likewise, the second conduit 221 may have alignedthird and fourth sections 225 and 226 that are situated on oppositesides of the internal chamber 222. The sections 223, 224, 225, and 226each may independently interconnect the internal chamber 222 to anexternal surface 227 of the fluid end 200.

A plunger 228 reciprocates within the body 201 to increase the pressureof fluid being discharged from the fluid end 200. As shown in FIG. 9,the plunger 228 may be disposed within the third section 225 of thesecond conduit 221. The plunger 228 is powered by an engine operativelyengaged with the fluid end 200. In high pressure hydraulic fracturingoperations, the engine preferably has a power output of at least 2,250horsepower. Valve seats 229 are also shown within the first conduit 220.The valve seats 229 may support valves, such as a ball valve, used tocontrol the movement of high pressure fluid within the body 201.

There are sealing areas in the fluid end 200 that experience the kind oferosion issues described above in plug valves. Similar to theconventional plug valve 100 depicted in FIG. 1, a number of componentsseal to the manifold body 201. Here, again, the sacrificial member forerosion, by design, is the body 201 instead of the less complex and lessexpensive mating component.

For example, the body 201 defines a discharge opening 202 that opensinto the first conduit 220. The discharge opening 202 depicted in theseembodiments is sealed closed by inserting a closure or discharge plug orcover 204 into the conduit 220 and securing it by advancing a retainingnut 206 into the body 201. The discharge plug 204 supports a seal 208that seals against the bore defining the discharge opening 202. FIG. 10is a simplified cross-sectional depiction of the discharge plug 204 thathas a surface 205 defining a recess 207 into which the seal 208 ismounted at an inner radial surface 211 of the radial seal 208.

In these illustrative embodiments the recess 207 is rectangular but thecontemplated embodiments are not so limited. The skilled artisanunderstands that the configuration of the recess 207 is largelydetermined by what shape is required to mount the type of seal selected.The recess 207 intersects an outer surface 215 of the discharge plug204, permitting the seal 208 to be sized so that a portion not mountedwithin the recess 207 extends beyond the outer surface 215 to pressinglyengage against the bore 209 defining the discharge opening 202. In thisconstruction the highly-pressurized corrosive and/or abrasive fluid canharsh fluid can be injected between the seal 208 and the bore 209,causing erosion of the seal surface formed by the bore 209. Thistechnology transfers that erosion wear from the body bore 209 to theless complex and less expensive discharge plug 204.

Fluid end bodies have conventionally been made of heat-treated carbonsteel, so it was not uncommon for the body 201 to crack before anysacrificial erosion of the body progressed to the point of creatingleakage between the discharge plug 204 and the bore 209. However,progress in the technology has introduced stainless steel bodyconstruction resulting in a significantly longer operating life. As aresult, this erosion is no longer negligible but is instead aconsideration for reducing erosion in modern fluid end construction. Oneleading source of bore 209 erosion in conventional fluid ends is theseal 208 mounted in the discharge plug 204 and extending therefrom toseal against a sealing surface formed by the body 201.

FIG. 11 is an exploded cross-sectional depiction of a fluid end 230 thatis constructed in accordance with this technology to, in numerousplaces, transfer the erosion wear from the body to the less complex andless expensive component that is sealed to the body. A manifold body 232forms a number of interconnected bores or conduits, including a firstconduit or discharge bore 234 forming a discharge opening 235 that issimilar to the discharge opening 202 in the conventional fluid end 200depicted in FIG. 9. The discharge bore 234 further defines an intakeopening 231 formed opposite the discharge opening 235. The term“discharge bore” for purposes of this description means the surfacedefining the discharge opening 235 into which a closure or dischargeplug 236 and a retaining nut 238 are installed, and the surface definingthe intake opening 231. For clarity, although FIG. 11 references thedischarge bore 234 as defining an upper end of the discharge opening 235where the retaining nut 238 attaches, the discharge bore 234 alsoreferences lower portions of the discharge opening 235 where thedischarge plug 236 seals to the body 232 and where the valve seat (notdepicted) seals to the body 232. Likewise, the discharge bore 234 alsoreferences upper portions of the intake opening 231. Generally, forpurposes of this description the discharge bore 234 formsmulti-dimensional diameters at different longitudinal locations of thedischarge opening 235 and intake opening 231.

The discharge opening 235 is sealed closed by inserting the dischargeplug 236 into the discharge opening 235 and securing it in place byadvancing the retaining nut 238. Unlike the conventional plug 204 inFIG. 9, however, the plug 236 does not have a seal mounted to it thatseals against the bore 234. Instead, the plug 236 defines a sealingsurface 237 for a seal (not depicted in FIG. 11) that is mounted in anendless groove or recess formed by a surface 239 of the body 232. Thesealing surface 237 is axially spaced between a first surface 251 and anopposite second surface 253 of the plug 236.

FIG. 12 is a simplified cross-sectional enlargement depicting theconstruction of the seal positioned within the surface 239 of the body232. The surface 239 forms an endless groove or recess 240 thatintersects the discharge bore 234. A seal 242 in these illustrativeembodiments is mounted in the recess 240 to include an outer radialsurface, and is thereby supported by the body 232. The recess 240 ischaracterized by a pair of parallel sidewalls joined by a base. Therecess 240 opens towards a centerline of the conduit within which it isformed. Alternatively, as shown by recess 266 in FIGS. 14-15, the recessmay open in a direction parallel to a centerline of the conduit withinwhich it is formed. As above, the rectangular-groove shape of the recess240 is merely illustrative and not limiting of the contemplatedembodiments. Any shape necessary to properly mount a desired seal iscontemplated, whether the seal is elastomeric, spring, metal, and thelike. As above, the recess 240 intersects the bore 234 permitting theseal 242 to be sized so that a portion of the seal 242 not contained inthe recess 240 extends beyond the recess 240 and beyond the bore 234 topressingly seal against the sealing surface 237 (FIG. 11) defined by thedischarge plug 236.

This seal construction depicted in FIG. 12 transfers the erosion wearfrom the body to the discharge plug. That significantly improves fluidend operations because repairs involving the discharge plug 236 aresignificantly less complex and less expensive than repairs involving thebody 232, which typically involve weld-repair. Furthermore,weld-repairing the body 232 makes it susceptible to premature fatiguecracking in the repaired area. Further, even more operating life can beachieved by applying an erosion-resistant surface treatment to the plug236, such as a high velocity oxygen fuel (HVOF) treatment, a tungstencarbide coating, material carburizing, and the like. Replacing insteadof repairing an eroded discharge plug 236 is typically feasible, makingit advantageously possible to repair a leaking valve constructedaccording to this technology in the field and thereby significantlyreducing down time.

Returning to FIG. 11, the body 232 has a surface 241 defining an endlessgroove or recess intersecting the bore 234 and configured to mount aseal (not depicted) that extends from the recess to seal against asealing surface formed by a discharge valve seat (not depicted).Similarly, the body 232 has a surface 243 forming another endless grooveor recess intersecting the bore 234 and configured to mount another seal(not depicted) that is sized to extend from the recess to seal against asealing surface formed by a suction valve seat (not depicted). Themultiple references to a same bore 234 is for purposes of ease ofdescription and is not narrowing of the contemplated embodiments of thistechnology. Whether the recesses defined by surfaces 241, 243 are formedin the same bore or different bores does not alter the scope of thecontemplated embodiments directed to the recess for mounting the seal isformed in the body, and a seal is mounted in the recess and from thereseals against a sealing surface of a component in a sealing engagementtherebetween.

Similarly, a suction bore 247 is sealed closed by inserting a closure orsuction plug or cover 244 defining a sealing surface 245 and securing itin place by advancing a retaining nut 246 in the body 232. Like the plug236, the sealing surface 245 is axially spaced between a first surface255 and an opposite second surface 261 of the plug 244. Again, the body232 in these illustrative embodiments has a surface 248 forming anendless groove or recess intersecting the bore 247 and configured formounting a seal (not depicted) extending from the recess and sealingagainst the sealing surface 245 of the suction plug 244. That transfersthe wear from the body 232 to the suction plug 244 in comparison topreviously attempted solutions and in accordance with the embodiments ofthis technology.

The body 232 also forms a plunger opening 250 sized to closely receive astuffing box sleeve 254 that is sealed in place by advancing a retainingnut 256. The stuffing box sleeve 254 is characterized by a tubularsleeve. The plunger 228, shown in FIG. 9, may be disposed within thestuffing box sleeve 254.

The opening 250 is formed in part by the plunger bore 252 having asurface 257 defining an endless groove or recess intersecting the bore252, into which a seal (not depicted) is mounted in these illustrativeembodiments. The suction bore 247 and the plunger bore 252 together formthe second conduit. Although these illustrative embodiments use a radialseal, the contemplated embodiments are not so limited. In alternativeembodiments other types of constructions are contemplated by thistechnology employing axial seals, crush seals, and the like.

FIG. 13 is a simplified cross-sectional depiction of the body 232 havingthe surface 257 forming the recess 258. Again, the recess 258 intersectsthe body bore 252 permitting a portion including an outer radial surfaceof a radial seal 260 to be mounted in the recess 258. Another portion ofthe seal 260 not mounted in the recess 258 extends from the recess 258to pressingly seal against the sealing surface 259 of the sleeve 254.Although in these depicted embodiments a radial seal is used, thecontemplated embodiments are not so limited. The skilled artisan readilyunderstands that other types of seals could be used instead of or inaddition to the radial seal depicted, such as axial seals, crush seals,and the like.

FIG. 14 depicts a number of additional endless grooves or recesses inthe body 232 for mounting various seals to transfer the wear away fromthe body 232 to the mating component in accordance with embodiments ofthis technology. For example, the body 232 has a surface 266 defining arecess 273 intersecting the body bore that defines the discharge opening235. Consistent with this whole description, this permits mounting anaxial seal 268 (not depicted in FIG. 14, see FIG. 15) in the recess 273,the seal 268 configured to extend from the recess 273 to seal against aleading face of the discharge plug 236 (FIG. 11). FIG. 15 is asimplified enlarged depiction of the body 232 having a surface 266defining the recess 273 into which an axial seal 268 is mounted. Inthese illustrative embodiments the seal 268 is configured to extendbeyond the body bore defining the discharge opening 235 to seal againstthe discharge plug 236 as it is urged downward by advancing theretaining nut 238 (FIG. 11).

Importantly, the simplified seal construction depicted in FIG. 15 andelsewhere is in no way limiting of the contemplated embodiments andscope of the claimed technology. In alternative embodiments a radialseal or a crush seal and the like can be employed to transfer theerosion wear from the body 232 to the mating component. A crush sealrefers to a seal construction that acts at least to some degree bothaxially and radially. For example, surface 272, shown in FIG. 14, formsa recessed corner having two walls that extend concentrically around thebore 252 (FIG. 11). The stuffing box sleeve 254 may be formed to haveside walls that fully overlie the corner section formed by surface 272when it is positioned in the bore 252. This allows the seal to act as acrush seal because it seals axially and radially against the sleeve 254.

Returning to FIG. 14, the body 232 can have other surfaces formingendless grooves or recesses for mounting various other seals. Forexample, surface 270 forms a recess for mounting a seal that isconfigured to seal against a sealing surface of a suction plug (notdepicted), like in FIG. 15. In the same way the body 232 can havesurfaces 272, 274, 276 forming recesses for mounting seals that areconfigured to seal against sealing surfaces of the stuffing box sleeve254 (FIG. 11), the discharge valve seat (not depicted), and the suctionvalve seat (not depicted), respectively. Likewise, the body 232 can havea surface 278 forming a recess for mounting a seal that is configured toseal against a suction manifold (not depicted). What's common in anyevent is the seal construction of this technology transfers the sealwear from the body 232 to the less complex and less expensive matingcomponent that is attached to the body 232.

FIG. 16 depicts the stuffing box sleeve 254 (FIG. 11) inserted into theplunger opening 250 so that a seal 260 mounted in the recess 258 formedby the surface 257 extends from that recess 258 and seals against thesealing surface 259 defined by the stuffing box sleeve 254. As thestuffing box sleeve 254 is inserted into this position air pressureforms in a space defined in the clearance gap between the outer diameterof the stuffing box sleeve 254 and the body bore defining the plungeropening 250 and between the seal 260 and a seal 286 at an opposing endof the stuffing box sleeve 254. The air pressure exerts a force urgingthe stuffing box sleeve 254 out of the plunger opening 250, complicatingmanufacture and degrading the seal integrity at the lower end of thestuffing box sleeve 254. A breather opening 284 can be formed betweenthat space and ambient space above the stuffing box sleeve 254 to ventthe air pressure.

FIG. 16 also depicts a conventional construction of the seal 286 that ismounted in a recess formed by the stuffing box sleeve 254 and extendsfrom that recess to seal against the body bore defining the plungeropening 250. The contemplated embodiments can include combinations ofthe conventional construction and the construction of this technologywhere other matters come into play. For example, without limitation, itcan be feasible to use a stuffing box sleeve 254 depicted in FIG. 16 ifit can be manufactured or otherwise acquired less expensively thanproviding the recess instead in the body 232, and if the particular seallocation is one that is not necessarily critical in its role for theoverall design for maintaining the highly-pressurized fluid in the flowpassage.

FIG. 16 also depicts employing the open-cylinder-shaped stuffing boxsleeve 254 and securing it in place by advancing the retaining nut 256(FIG. 11). That construction is illustrative and in no way limiting ofthe contemplated technology. Other configurations can be employed aswell. For example, the skilled artisan understands that a conventionalstuffing box can be employed that combines the stuffing box sleeve 254and the retaining nut 256, unitarily, into one component that has arecess for supporting a seal configured to seal against the body boredefining the plunger opening 235. In other conventional constructions astuffing box without that recess is used in combination with a sealcarrier insert that mates with the stuffing box and provides the recessfor mounting the seal. In yet other contemplated embodiments thestuffing box sleeve 254 can be modified to a construction combining asubstantially cylindrical-shaped stuffing box to which is mated a sealsurface insert that provides the sealing surface 259 (FIG. 11).

Returning momentarily to FIG. 11, the sleeve 254 also protects the bore252 from erosion by providing an inner diameter surface 264 againstwhich the stuffing box packing (not depicted) seals. That, again, bydesign transfers the wear from the body 232 to the less complex and lessexpensive sleeve 254.

Summarizing, this technology contemplates a high pressure fluid flowapparatus constructed of a body defining a flow passage, a closuremounted to the body, and a means for sealing between the body and theclosure. For purposes of this description and meaning of the claims theterm “closure” means a component that is attached or otherwise joined tothe body to provide a high-pressure fluid seal between the body and theclosure. In some embodiments such as the described valve embodiments“closure” encompasses a moving component that is selectivelypositionable to control the fluid flow through the valve, such as theplug described and other components such as but not limited to a wedge,a clapper, a ball, a segment, and the like. In some embodiments such asthe described fluid end embodiments “closure” encompasses nonmovingcomponents joined to the body to seal an opening such as but not limitedto the discharge plug, suction plug, discharge valve seat, suction valveseat, stuffing box sleeve, discharge flange, suction manifold, and thelike. The term “means for sealing” means the described structures andstructural equivalents thereof that mount a seal to a body instead of amating closure to transfer the wear in comparison to previouslyattempted solutions from the body to the closure. “Means for sealing”expressly does not encompass previously attempted solutions that mount aseal to the closure to extend therefrom and seal against the body.

The various features and alternative details of construction of theapparatuses described herein for the practice of the present technologywill readily occur to the skilled artisan in view of the foregoingdiscussion, and it is to be understood that even though numerouscharacteristics and advantages of various embodiments of the presenttechnology have been set forth in the foregoing description, togetherwith details of the structure and function of various embodiments of thetechnology, this detailed description is illustrative only, and changesmay be made in detail, especially in matters of structure andarrangements of parts within the principles of the present technology tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. An apparatus, comprising: a fluid end housing in which a plurality ofbores, including a plunger bore and a suction bore, are formed, whereinthe plunger bore has a first segment and a second segment, wherein thefirst segment has a groove and is located closer to the suction borethan the second segment, and wherein the second segment has a greaterdiameter than the first segment; a sleeve installed within the plungerbore, wherein the sleeve includes: a first sleeve portion installedwithin the first segment of the plunger bore; and a second sleeveportion installed within the second segment of the plunger bore, whereinthe second sleeve portion has greater inner and outer diameters than thefirst sleeve portion; a retainer attached to the fluid end housing andengaged with the sleeve to secure the sleeve within the plunger bore;stuffing box packing located within the second sleeve portion; and aseal positioned in the groove and engaging the first sleeve portion. 2.The apparatus of claim 1, wherein the inner and outer diameters of thefirst sleeve portion are constant; and wherein the inner and outerdiameters of the second sleeve portion are constant.
 3. The apparatus ofclaim 1, wherein the retainer includes a first threaded surface thatcouples to a corresponding second threaded surface around the secondsegment of the plunger bore.
 4. The apparatus of claim 1, wherein afirst portion of the retainer is disposed within the second segment ofthe plunger bore and a second portion of the retainer is disposedoutside of the fluid end housing.
 5. The apparatus of claim 1, whereinthe retainer, sleeve, and housing are separate components.
 6. Theapparatus of claim 1, wherein the sleeve extends from a front surface toa rear surface, wherein the first sleeve portion is adjacent the frontsurface, and wherein the second sleeve portion is adjacent the rearsurface.
 7. The apparatus of claim 1, wherein the sleeve includes athird sleeve portion that includes at least one groove around anexterior of the third sleeve portion; wherein the third sleeve portionis installed within the second segment of the plunger bore such that thesecond sleeve portion is closer to the first sleeve portion; and whereinthe stuffing box packing is located within the second and third sleeveportion.
 8. The apparatus of claim 7, wherein the sleeve includes afourth sleeve portion between the first and second sleeve portions,wherein the fourth sleeve portion is in contact with the fluid endhousing and is shaped to: transition, at a first transition surface onan interior of the sleeve, from the greater inner diameter of the secondsleeve portion to an inner diameter of the first sleeve portion; andtransition, at a second transition surface on an exterior of the sleeve,from the greater outer diameter of the second sleeve portion to an outerdiameter of the first sleeve portion.
 9. The apparatus of claim 1,wherein the retainer is removable from the apparatus without removingthe stuffing box packing; and wherein the stuffing box packing isremovable from an interior of the second sleeve portion without removingthe sleeve from the plunger bore.
 10. An apparatus, comprising: a fluidend housing in which a plurality of bores, including a plunger bore anda suction bore, are formed, wherein the plunger bore has a first segmentand a second segment, wherein the first segment has a groove and islocated closer to the suction bore than the second segment, and whereinthe second segment has a greater diameter than the first segment; a sealthat is positioned in the groove; and a closure installed within theplunger bore and configured to receive a plunger, wherein the sealengages an exterior surface of the closure.
 11. The apparatus of claim10, further comprising: a retainer securing the closure within theplunger bore.
 12. The apparatus of claim 10, in which the closurecomprises: a cylindrical first portion joined to a cylindrical secondportion; in which the second portion is sized to correspond with thesecond segment of the plunger bore; and in which the first portion issized to correspond with the first segment of the plunger bore.
 13. Theapparatus of claim 10, in which the groove comprises: a base joined totwo parallel side walls.
 14. The apparatus of claim 11, in which theretainer has opposed first and second surfaces; in which the closure hasopposed first and second surfaces; and in which the first surface of theclosure abuts the second surface of the retainer.
 15. The apparatus ofclaim 10, further comprising: a stuffing box packing installed withinthe closure and configured to surround the plunger.
 16. The apparatus ofclaim 15, in which the stuffing box packing is removable from the fluidend housing without removing the closure.
 17. The apparatus of claim 11,wherein the retainer, closure, and housing are separate components. 18.The apparatus of claim 12, further comprising: a stuffing box packinginstalled within the second portion of the closure and configured tosurround the plunger.
 19. The apparatus of claim 12, in which a maximumdiameter of the second portion is greater than a maximum diameter of thegroove.
 20. The apparatus of claim 1, a maximum diameter of the closureis greater than a maximum diameter of the groove.